Severe Thunderstorm Warning 197, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
355 PM CDT SUN MAY 27 2001

STRONG/SEVERE THUNDERSTORMS ONGOING AT THIS TIME ACROSS SOUTHEAST KS
AND NORTHEAST OK NEAR THE KS BORDER.  AMS VERY UNSTABLE ACROSS THE
AREA...AND ACTIVITY EXPECTED TO CONTINUE TO SPREAD SLOWLY TO THE SE
AND SSE INTO THE EARLY EVENING HOURS.  STORMS EXPECTED TO THEN
WEAKEN WITH FOCUS TURNING TOWARD ADDITIONAL COMPLEX OF STORMS NOW
DEVELOPING OVER WESTERN KS.

OVERNIGHT MCS EXPECTED TO DROP FROM WESTERN KS DOWN ACROSS OK
AFFECTING MAINLY SOUTHERN PARTS OF THE AREA LATE TONIGHT INTO MONDAY
MORNING.  STILL UNSURE HOW ANY OUTFLOWS OR LINGERING BOUNDARIES FROM
CURRENT CONVECTION WILL AFFECT STORMS LATER ON.  WILL GENERALLY GO
WITH LIKELY POPS OVER THE ENTIRE AREA FOR THE TONIGHT PERIOD...AND
MENTION POSSIBILITY OF SEVERE ALL AREAS.  NORTHEAST OK AND NORTHWEST
AR FOR CURRENT ACTIVITY...AND SOUTHEAST OK FOR LATE NIGHT STORMS.

WILL CONTINUE TO SEE NORTHWESTERLY FLOW PATTERN THROUGH MUCH OF THE
UPCOMING WEEK...SO ADDITONAL WEAK IMPULSES WILL KEEP CHANCE POPS IN
THE FORECAST THROUGH FRIDAY.  WILL CUT DAYTIME TEMPS SOME FOR
TOMORROW DUE TO EXPECTED CLOUD COVER FROM PASSING MCS...THEN LITTLE
DAY TO DAY CHANGE IN TEMPS FOR MUCH OF THE REST OF THE WEEK.

FCSTID = 4
TUL   64  78  62  82 /  70  30  30  30
FSM   64  78  62  83 /  60  40  30  30
MLC   64  78  62  83 /  60  40  30  30
BVO   60  78  58  80 /  70  30  30  30
FYV   60  75  56  78 /  70  30  30  30
BYV   60  75  56  78 /  60  30  30  30
MIO   61  77  58  79 /  70  30  30  30
MKO   64  78  62  82 /  70  40  30  30
F10   64  78  62  82 /  70  40  30  30
HHW   63  80  63  83 /  60  50  30  30

.TSA...
AR...SEVERE THUNDERSTORM WATCH UNTIL 700 PM CDT SUNDAY FOR ZONES
ARZ001...ARZ010.

OK...SEVERE THUNDERSTORM WATCH UNTIL 700 PM CDT SUNDAY FOR ZONES
OKZ054>064...OKZ067>069.

ARZ001-002-010-011-019-020-029-OKZ049-053>076-281100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
100 PM CDT SUN MAY 27 2001

...SCATTERED SEVERE THUNDERSTORMS EXPECTED THIS AFTERNOON AND
   EVENING ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...
...A FEW SEVERE THUNDERSTORMS ARE EXPECTED OVERNIGHT...MAINLY
   IN SOUTHEAST OKLAHOMA...

A STATIONARY FRONT WAS LOCATED ACROSS SOUTHEAST KANSAS EXTENDING
SOUTHEAST INTO NORTHWEST ARKANSAS EARLY THIS AFTERNOON. SCATTERED
STRONG TO SEVERE THUNDERSTORMS HAVE ALREADY DEVELOPED ALONG THIS
BOUNDARY IN SOUTHEAST KANSAS. THE THUNDERSTORM ACTIVITY IS EXPECTED
TO INCREASE IN COVERAGE AND INTENSITY...MOVING SOUTHEAST INTO EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS THIS AFTERNOON AND EARLY EVENING.
SOME OF THESE STORMS WILL LIKELY BE SEVERE WITH LARGE HAIL AND
DAMAGING WINDS.

A SECONDARY COMPLEX OF SEVERE THUNDERSTORMS IS FORECAST TO DEVELOP
OVER NORTHWEST OKLAHOMA THIS EVENING...POSSIBLY MOVING INTO
SOUTHEAST OKLAHOMA AFTER MIDNIGHT. THESE STORMS COULD ALSO PRODUCE
LARGE HAIL...DAMAGING WINDS AND VERY HEAVY RAINFALL.

.SPOTTER ACTIVATION...
ACTIVATION OF STORM SPOTTER GROUPS WILL LIKELY BE REQUIRED THIS
AFTERNOON ACROSS PORTIONS OF EASTERN OKLAHOMA AND NORTHWEST
ARKANSAS.

.DISCUSSION...
A STATIONARY BOUNDARY WAS LOCATED OVER SOUTHEAST KANSAS EARLY THIS
AFTERNOON.  STRONG THUNDERSTORMS HAVE ALREADY DEVELOPED ALONG THE
BOUNDARY WHERE WEAK LOW LEVEL MOISTURE CONVERGENCE IS OCCURRING.
SOUTH OF THE BOUNDARY...THE AIRMASS HAS BECOME VERY UNSTABLE WITH
CAPE VALUES BETWEEN 2500-3500 J/KG...AND LIFTED INDICES BETWEEN -7
AND -9 C. CONVECTION WILL LIKELY BECOME BETTER ORGANIZED...AS STORMS
MOVE SOUTHEAST INTO A MORE UNSTABLE AIRMASS. GIVEN THE INSTABILITY
IN PLACE...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY WITH THESE
STORMS.

AN ADDITIONAL AREA OF SEVERE THUNDERSTORMS ARE FORECAST TO DEVELOP
ACROSS PORTIONS OF NORTHWEST OKLAHOMA BY EARLY EVENING. THESE STORMS
WILL INITIALLY BE SUPERCELL THUNDERSTORMS...BUT ARE EXPECTED TO
ORGANIZE INTO A CONVECTIVE COMPLEX THAT WILL MOVE RAPIDLY
SOUTHEAST...MAINLY INTO SOUTHEAST OKLAHOMA DURING THE OVERNIGHT
HOURS. THE PRIMARY THREAT FROM THESE THUNDERSTORMS WILL BE
STRONG DAMAGING WINDS.  IF OUTFLOW BOUNDARIES FROM THE CONVECTION
THIS AFTERNOON PUSHES THROUGH SOUTHEAST OKLAHOMA THIS EVENING...THE
SECONDARY THUNDERSTORM COMPLEX MAY TRACK FURTHER WEST...LIMITING THE
SEVERE WEATHER THREAT IN SOUTHEAST OKLAHOMA OVERNIGHT.

THREAT TABLE
VALID THROUGH 1200 UTC MONDAY

THREAT AREA 1...EASTERN OKLAHOMA/NORTHWEST ARKANSAS
THUNDERSTORM PROBABILITY...60
SEVERE PROBABILITY IF STORMS OCCUR...70
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...20

THREAT AREA 2...SOUTHWEST OF A LINE FROM PAWNEE TO TALIHINA
THUNDERSTORM PROBABILITY...80
SEVERE PROBABILITY IF STORMS OCCUR...60
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...10

THREAT AREAS DEFINE THE GREATEST RISK. PROBABILITIES ARE IN PERCENT.
SIGNIFICANT SEVERE IS DEFINED AS F1 OR GREATER WIND/TORNADO DAMAGE
AND/OR GOLFBALL SIZE HAIL OR LARGER.

RELATED GRAPHICAL INFORMATION CAN BE FOUND AT...
HTTP://WWW.SRH.NOAA.GOV/TULSA

.OTHER HAZARDS...
LOCALLY HEAVY RAINFALL WILL BE POSSIBLE DURING THE OVERNIGHT HOURS
WITH THE COMPLEX OF THUNDERSTORMS EXPECTED TO MOVE ACRZOSS SOUTHEAST
OKLAHOMA. ISOLATED FLOODING WILL BE POSSIBLE...BUT MAINLY LIMITED TO
LOW LYING AND POOR DRAINAGE AREAS. WIDESPREAD FLASH FLOODING IS NOT
EXPECTED.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
358 PM CDT SUN MAY 27 2001

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

031z4 PM    FORAKER                   OK    .88 INCH HAIL
05/27/01   OSAGE                           REPORTED BY PUBLIC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
400 PM CDT SUN MAY 27 2001

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

035*0 PM    4 W PAWHUSKA              OK    60 MPH TSTM GUST
05/27/01   OSAGE                           REPORTED BY SPOTTER